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Transition metal-free half-metallicity recently has been the subject of intense research activity due to its potential in spintronics application. By employing density functional theory calculations, we revealed that F-intercalated GaN bilayers exhibit robust p orbital-based half-metallicity against the intercalant concentration and biaxial strain of −10% to 10%. The stable half-metallicity results from a spontaneous phase transition through Stoner instability and can be attributed to unusually high density of states near the Fermi level due to the quasi-flat bands. These findings provide a strategy to design transition-metal free half-metallic materials for futuristic spintronic applications. [ABSTRACT FROM AUTHOR]

Plasmonic metal nanostructures have been widely applied in photodetectors for the enhanced light response range and sensitivity. In contrast, photodetection based on surface plasmon effect of the emerging plasmonic nonmetals has not been investigated. Here, single nonmetal plasmonic WO3−x nanosheets were used as the sensing material for UV–Vis–NIR broad spectral photodetectors. The plasmonic WO3−x nanosheets were synthesized by solvothermal and follow-up thermal treatment in a hydrogen-containing atmosphere, which exhibited a localized surface plasmon resonance (LSPR) band centered at 899 nm with broad spectral absorption spanned from UV to NIR. Then photodetectors fabricated facilely by depositing Au electrodes on a film of WO3−x nanosheets showed sensitive response for the regulation of conductance through the plasmonic hot free charge carriers. The responsivity and detectivity were 52 mA/W and 1.46 × 108 Jones under an incident light with a wavelength of 980 nm with an ultralow bias of 0.01 V, and went up to 538 mA/W and 4.75 × 108 Jones under 0.1 V. The results demonstrate the great potential of nonmetal plasmonic materials for photodetection. [ABSTRACT FROM AUTHOR]

We evaluated the perpendicular magnetic anisotropy (PMA) features of a hybrid [CoO/Pd]2/[Co/Pd]7 multilayer (ML) matrix under annealing in which the [CoO/Pd]2 bottom layer was inserted. Annealing allowed for the diffusion of oxygen atoms existing in the inserted [CoO/Pd]2 layer, leading to an atomic structural reconfiguration event. The hybrid matrix was crucial to result in a higher effective anisotropy energy (3.40 Merg/cc) than an ordinary [Co/Pd]7 ML matrix (1.25 Merg/cc) under annealing at 450 °C. X-ray photoelectron spectroscopy confirmed the presence of Co-O bonding states and annealing dependent oxygen atom diffusion. The possible nature of the enhanced PMA features is discussed. [ABSTRACT FROM AUTHOR]

We present a study of the role of oxygen vacancies on the atomic and electronic structure and transport properties on a 20 nm thick La0.7Ca0.3MnO3 film grown by the pulsed laser deposition method on a SrTiO3 (001) substrate. The results show that oxygen vacancies induce an atomic structure modification characterized by the movement of the La/Ca cations to the perovskite regular position, by the reduction of the MnO6 basal plane rotation, and by a cooperative tilting of the octahedra along the out-of-plane direction. The out-of-plane lattice parameter increases due to the reduction of the Mn valence upon oxygen vacancies creation. As a consequence, a shift of the Metal-to-Insulator transition to lower temperatures is found to occur. We discuss the influence of the competitive phenomena of manganese valence and Mn-O-Mn bond distortion on the transport properties of manganite thin films. [ABSTRACT FROM AUTHOR]

We studied current-voltage characteristics of nanoscale pn diodes having the junction formed in a laterally patterned ultrathin silicon-on-insulator layer. At temperatures below 30 K, we observed random telegraph signal (RTS) in a range of forward bias. Since RTS is observed only for pn diodes, but not for pin diodes, one dopant among phosphorus donors or boron acceptors facing across the junction is likely responsible for potential changes affecting the current. Based also on potential measurements by low-temperature Kelvin probe force microscope, RTS is ascribed to trapping/detrapping of carriers by/from a single dopant near the farther edge of the depletion region. [ABSTRACT FROM AUTHOR]

We present here ultra-compact high-Q Fano resonance filters with displaced lattices between two coupled photonic crystal slabs, fabricated with crystalline silicon nanomembrane transfer printing and aligned e-beam lithography techniques. Theoretically, with the control of lattice displacement between two coupled photonic crystal slabs layers, optical filter Q factors can approach 211 000 000 for the design considered here. Experimentally, Q factors up to 80 000 have been demonstrated for a filter design with target Q factor of 130 000. [ABSTRACT FROM AUTHOR]

The interaction of H and Fe clusters of up to nine atoms were investigated within a density functional theory. Calculations indicate that one gas-phase Fe atom can absorb ten H atoms, an amount 2.5 times more than methane (CH4). The magnetic state of Fe atoms non-uniformly decrease by increasing the number of H. The bonding of Fe-H in FeH clusters consists of charge transfer and electron pairing. Thus, two types of bondings are involved. The bond mechanism is general in nature within transition metal clusters, bringing insight for the development of heterogeneous catalyst and hydrogen storage materials. [ABSTRACT FROM AUTHOR]

Superconducting boron-doped silicon films prepared by gas immersion laser doping (GILD) technique are analyzed by atom probe tomography. The resulting three-dimensional chemical composition reveals that boron atoms are incorporated into crystalline silicon in the atomic percent concentration range, well above their solubility limit, without creating clusters or precipitates at the atomic scale. The boron spatial distribution is found to be compatible with local density of states measurements performed by scanning tunneling spectroscopy. These results combined with the observations of very low impurity level and of a sharp two-dimensional interface between doped and undoped regions show that the Si:B material obtained by GILD is a well-defined random substitutional alloy endowed with promising superconducting properties. [ABSTRACT FROM AUTHOR]

Doping of silicon-on-insulator layers with sulfur to concentrations far above equilibrium by ion implantation and pulsed laser melting can result in large concentration gradients. Photocarriers generated in and near the impurity gradient can separate into different coplanar transport layers, leading to enhanced photocarrier lifetimes in thin silicon-on-insulator films. The depth from which holes escape the heavily doped region places a lower limit on the minority carrier mobility-lifetime product of 10-8 cm2/V for heavily sulfur doped silicon. We conclude that the cross-section for recombination through S impurities at this concentration is significantly reduced relative to isolated impurities. [ABSTRACT FROM AUTHOR]

We present hybrid density functional calculations suggesting that magnetism in cubic SrTi1-xCoxO3-δ (STCO) with x = 0.25 is sensitive to the nearest neighbor arrangement of the Co and the presence of oxygen vacancies. Spin polarized calculations for x = 0.25 in which the nearest neighbor (nn) Co spacing is a, [formula] or [formula] with a the lattice parameter predict lowest energies for the [formula] nn separation and favor the ferromagnetic state. Oxygen deficiency (δ=0.125) lowers the average Co valence state and favors mixed valence and spin states (high spin for the Co adjacent to the vacancy and low for the non-adjacent Co), an increase of the band gap and an expansion of the lattice parameter compared to stoichiometric STCO in which both Co ions are low spin. Predicted configurations of the two neighboring Co ions are (t2g5eg0, t2g5eg0) and (t2g4eg2, t2g6eg0) with average 1.0 and 1.6 μB/Co for stoichiometric and 1-O-vacancy systems, respectively. [ABSTRACT FROM AUTHOR]

We show direct evidence for importance of the interface resistance to electrically create large spin accumulation in silicon (Si). With increasing the thickness of the tunnel barrier in CoFe/MgO/n+-Si devices, a marked enhancement of spin accumulation signals can be observed in the electrical Hanle-effect measurements. To demonstrate room-temperature detection of the spin signals in three-terminal methods, the influence of the spin absorption from Si into CoFe through a tunnel barrier should be taken into account. [ABSTRACT FROM AUTHOR]

For high power electronics, diamond is a promising semiconductor with phosphorus being the current substitutional donor. However, up to now, in (100) oriented grown diamond, only a small fraction of phosphorus atoms is incorporated in substitutional sites (<30%) and the epilayer surface exhibits macrosteps. In this work, we present a (100) phosphorus-doped diamond epilayer where ∼100% of the phosphorus atoms are incorporated in substitutional sites. The film exhibits a low surface roughness (RMS = 0.5 nm). Our epilayer is conductive (ρ = 5.0 × 106 Ω · cm at 300 K) and neutral phosphorus are detected in infrared absorption. [ABSTRACT FROM AUTHOR]

A nonequilibrium argon plasma jet with oxygen addition, generated in a planar dielectric duct and issuing into ambient air with one edge stuck on a dielectric plane, is reported for the first time. This argon-oxygen plasma jet can be operated at low applied voltage as a filamentary discharge at atmospheric pressure. The addition of a small amount of oxygen results in the increase of produced ozone concentration and continuous emissions of centering at about 185 nm, 205 nm, 230 nm, and 253 nm. The synergistic generation of short wavelength ultraviolet emissions and active species is significantly important for plasma applications. [ABSTRACT FROM AUTHOR]

A light-trapping scheme for normal incidence Ge-on-Si photodiodes, utilizing needle-like black silicon nanostructures is presented. Simulations reveal that light absorption in thin rear Ge films can be enhanced several times due to both the antireflection and the scattering effect of the nanostructure. It is shown that especially films with thicknesses ≤100 nm benefit from the black silicon nanostructure, e.g., resulting in a 5 to 10 times higher absorptance at 1500 nm for a 100 nm thick film. Theoretical predictions are experimentally proved by reflectance-transmittance measurements of crystalline Ge films sputtered on black silicon substrates. [ABSTRACT FROM AUTHOR]

Although light-induced degradation (LID) in crystalline silicon is attributed to the formation of boron-oxygen recombination centers, copper contamination of silicon has recently been observed to result in similar degradation. As positively charged interstitial copper stays mobile at room temperature in silicon, we show that the bulk copper concentration can be reduced by depositing a large negative charge onto the wafer surface. Consequently, light-induced degradation is reduced significantly in both low- and high-resistivity boron-doped Czochralski-grown silicon. [ABSTRACT FROM AUTHOR]

A two-port silicon-based micromechanical beam resonator driven at its high-stiffness locations has been proposed with enhanced power handling as compared with the same resonator but using conventional drive/sense configurations. The key to attaining superior power handling relies on the electrode arrangements where critical handling power (or Duffing-nonlinear bifurcation power) becomes much higher by driving the resonator at its high-stiffness locations than low-stiffness areas. In this work, resonators using high-stiffness driving approach exhibit around 20× (20 times) power handling improvement as compared to low-stiffness driving counterpart while the motional impedances in both cases are the same under linear operation. [ABSTRACT FROM AUTHOR]

We demonstrate the design, fabrication, transmission spectrum measurement, and near-field characterization of a parabolic tapered one-dimensional photonic crystal cavity in silicon. The results shows a relatively high quality factor (∼43 000), together with a small modal volume of ∼1.1(λ/n)3. Moreover, the design allows repeatable device fabrication, as evident by the similar characteristics obtained for several tens of devices that were fabricated and tested. These demonstrated 1D PhC cavities may be used as a building block in integrated photonic circuits for optical on-chip interconnects and sensing applications. [ABSTRACT FROM AUTHOR]

We propose a scheme for achieving negative differential thermal conductance in near-field electromagnetic thermal transfer. As an example, we show that the scheme can be implemented with two slabs of silicon carbide brought in close proximity to each other. We also describe how a bistable thermal switch can be constructed in this manner. [ABSTRACT FROM AUTHOR]

An effective non-metal (N) and non-transition metal (Sb) passivated co-doping approach is proposed to improve the photoelectochemical performance of rutile TiO2 for water-splitting by using first-principles calculations. It is found that the band edges of N + Sb co-doped TiO2 match with the redox potentials of water, and a narrow band gap (2.0 eV) is achieved for enhanced visible light absorption. The compensated donor (Sb) and acceptor (N) pairs could prevent the recombination of photo-generated electron-hole pairs. In addition, the N + Sb defect pairs tend to bind with each other, which could enhance the stability and N concentration of the system. [ABSTRACT FROM AUTHOR]

Using a high-numerical-aperture lens, we studied strain relaxation in the [110]-oriented strained-silicon-on-insulator (SSOI) stripes. A complete set of Si optical phonon Raman bands was observed. For a 50 nm thick SSOI, the symmetrical biaxial tensile stress in a relatively wide stripe is found to transform to the uniaxial [110] stress at its edge. The same uniaxial stress is observed in the narrow stripes with widths <200 nm, the value, probably, being a critical width for a complete SSOI transverse stress relaxation. [ABSTRACT FROM AUTHOR]

The interaction between chemisorbed oxygen adatoms (O2(ad)-) and oxygen vacancies associated with the formation/rupture of conductive filaments dominates the switching yield of ZnO, which is also confirmed by the fact that the reduction of SET/RESET voltage with the temperature. The pronounced surface effect-induced conductivity lowering due to O2(ad)- chemisorption leads to increased resistance of high resistance state (HRS). The current decay of the HRS with increased temperatures/times is owing to the severe O2(ad)- chemisorption as Joule heating is continuously applied. The statistical analysis for over 400 cells provides essential evidence for evaluating the surface effect on resistive switching. [ABSTRACT FROM AUTHOR]

We report on wavelength conversion through four-wave-mixing in silicon slot-waveguides with embedded silicon nanocrystals. The combination of strong optical confinement and Si:nc nonlinearity provides a huge waveguide nonlinear coefficient γ = 1100 W-1m-1. Moreover, the improvement in the fabrication procedure allowed a loss reduction with respect to previous reported structures, enabling the achievement of an extreme value for the conversion efficiency which represents the best result ever reported in the scientific literature. [ABSTRACT FROM AUTHOR]

The nitrogen-doped Ge2Sb2Te5 (GST) programmable metallization cell is investigated to address the low switching voltage and need for a high resistance ratio, which are critical issues for the filed-programmable gate array (FPGA) configuration. Nitrogen doping of GST yields Ge-N covalent bonds, as confirmed by x-ray photoelectron spectroscopy and Raman spectroscopy; this increases the resistivity of GST. Consequently, an excellent resistance ratio (∼107) with appropriate operating voltage and stable retention properties more than for 104 s at 85 °C are achieved. The results indicate that the film is a suitable alternative candidate for the logic switch in static-random-access-memory-based FPGA technology. [ABSTRACT FROM AUTHOR]

Accurate prediction of the Schottky barrier heights (SBHs) from first principles is important for contact and device technologies. Ab initio simulations based on widely used local density approximation and generalized gradient approximation significantly underestimate the SBHs. By modeling CoSi2-Si and NiSi2-Si contacts using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional calculations, we demonstrate that HSE hybrid functional simulations can predict the SBHs in agreement with experiments. Furthermore, the effects of interfacial dopants and metal induced gap states are examined by ab initio hybrid functional simulations. [ABSTRACT FROM AUTHOR]

We report n-type conductivity in phosphorus ion implanted ultrananocrystalline diamond films annealed at 800 °C and above. The amorphous carbon transits to diamond with an increase of stress after 900 °C annealing, which exhibits lower resistivity with Hall mobility of 143 cm2/Vs. After 1000 °C annealing, the diamond transits to amorphous carbon with the stress release, which has higher carrier concentration and lower Hall mobility. Both P+-implanted nano-sized diamond grains and amorphous carbon give contributions to the n-type conductivity in the films. The microstructure evolution and electrical properties are relative to the hydrogen diffusion and desorption under high temperature annealing. [ABSTRACT FROM AUTHOR]

We report enhanced reflection displayed by arrays of silicon based inverted nanocones. Theoretical studies suggest that such arrays display enhanced reflection and photonic band gaps within the optical and near infrared regions. Measured results show three to four fold enhancement in reflection and agree well with calculations. Such arrays can be used to enhance infrared reflection in photovoltaic devices which mostly contribute towards heating. [ABSTRACT FROM AUTHOR]

Photoluminescence imaging is now a widely used characterization tool for silicon bricks, wafers sliced from these bricks and for completed silicon devices, particularly solar cells. Analytical solutions for the spectral distribution of photoluminescence are reported showing the dependence on wavelengths of both exciting and emitted light and on test specimen doping levels, surface recombination velocities, carrier diffusion lengths, and front and rear reflection. [ABSTRACT FROM AUTHOR]

The effect of the induced electron traps by oxygen plasma treatment on transfer characteristics of organic thin film transistors (OTFTs) was researched in this study. From the observed result, the relationship between electron trapping and electrical stability of OTFTs was discussed. It is shown that oxygen plasma treatment may lead to a shift of the threshold voltage towards positive gate-source voltages and an increase in the mobility, resulting from the incorporation of oxygen and the passivation of the defects in the grain-boundary region. It is found that the electrical stability mainly arises from the increased long-lifetime electron-trap density. [ABSTRACT FROM AUTHOR]

Deformation, plasticity, and flow in silica-based glasses have been studied for decades, and yet important questions remain about the atomistic mechanisms underlying these processes. Our molecular dynamics simulations of nanoindentation indicate that these mechanical processes have a unified underlying atomistic mechanism. The simulations reveal that indentation nucleates under-coordinated silicon and oxygen defects, which migrate by switching bonds in string-like processes. We also observe defect annihilation in the plastic region underneath and the pileup region around the indenter. These defects have also been observed in simulations of nanovoid coalescence under hydrostatic tension and in nanovoid deformation and breakup in shearing silica glass. [ABSTRACT FROM AUTHOR]

Textured interfaces in thin-film silicon solar cells improve the efficiency by light scattering. A technique to get experimental access to the angular intensity distribution (AID) at textured interfaces of the transparent conductive oxide (TCO) and silicon is introduced. Measurements are performed on a sample with polished microcrystalline silicon layer deposited onto a rough TCO layer. The AID determined from the experiment is used to validate the AID obtained by a rigorous solution of Maxwell's equations. Furthermore, the applicability of other theoretical approaches based on scalar scattering theory and ray tracing is discussed with respect to the solution of Maxwell's equations. [ABSTRACT FROM AUTHOR]

Coherent x-ray diffraction was used to study the relaxation in single ultrathin strained silicon structures with nanoscale accuracy. The investigated structure was patterned from 20 nm thick strained silicon-on-insulator substrate with an initial biaxial tensile strain of 0.6%. Two-dimensional maps of the post-patterning relaxation were obtained for single 1 × 1 μm2 structures. We found that the relaxation is localized near the edges, which undergo a significant contraction due to the formation of free surfaces. The relaxation extent decreases exponentially towards the center with a decay length of 50 nm. Three-dimensional simulations confirmed that over-etching is needed to explain the relaxation behavior. [ABSTRACT FROM AUTHOR]

We use an elastomer as infill material for a photonic crystal. As a result of the thermal-expansion-induced strongly negative thermal optical coefficient, this material is highly suitable for thermal tuning of the transmission of a cavity. This is demonstrated by global infilling of a hole-type silicon photonic crystal slab and global thermal tuning. In the temperature range 20-60 °C the cavity peak shows a pronounced elastomer-induced blue shift of 2.7 nm, which amply overcompensates the red shift arising from the thermo-optic property of the silicon. These results qualify the elastomer for tuning by local optical heating. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations of a dislocation based mechanism for void formation in silicon are presented. By studying a moving solid-liquid interface in Si, we observe the formation of dislocation loops on (111) facets consisting of coherency and anticoherency dislocations, which disband within nanoseconds into vacancy clusters of 10 or more vacancies. These vacancy clusters can act as nucleation seeds for the experimentally observed octahedral single and double voids. [ABSTRACT FROM AUTHOR]

Recent experimental breakthroughs have demonstrated that the electron spin in silicon can be reliably injected and detected as well as transferred over distances exceeding 1 mm. We propose an on-chip communication paradigm which is based on modulating spin polarization of a constant current in silicon wires. We provide figures of merit for this scheme by studying spin relaxation and drift-diffusion models in silicon. [ABSTRACT FROM AUTHOR]

Superprotonic conduction in the LiH2PO4 system has been studied by means of high-resolution nuclear magnetic resonance measurements, which enabled us to distinguish dynamics of the two different hydrogen bonds in the structure. The protonic motion, primarily associated with the longer hydrogen bond, rather than the Li ionic motion, was revealed to dictate the extraordinarily high electrical conductivity of the system. [ABSTRACT FROM AUTHOR]

The compositional dependence of trap density and origin in thin silicon oxynitride (SiOxNy) films deposited by the low pressure chemical vapor deposition method was investigated using spin dependent Poole-Frenkel (SDPF) current technique. SDPF detected two kinds of traps, K-center (N3=Si·, where means a dangling bond) and K′-center (N2O=Si·). With increasing oxygen concentration, the amount of K-center decreases. On the other hand, K′-center increases up to O/O+N=0.25 and then it decreases. We propose the model that the change in the film strain by oxygen atoms induces these phenomena. [ABSTRACT FROM AUTHOR]

The experimental evidence of laser transition type in bismuth-doped silica fibers operating at different spectral bands is presented. Spectrally resolved transient (relaxation) oscillations studied for a Bi-doped fiber laser at room and liquid-nitrogen temperatures allow to identify the three- and four-level energy bands. 1.18 μm short-wavelength band is found to be a three-level system at room temperature with highly populated terminal energy level of laser transition. The depopulation of ground level by cooling the fiber down to liquid-nitrogen temperature changes the transition to four-level type. Four-level energy transition distinguished at 1.32 μm exhibits the net gain at room temperature. [ABSTRACT FROM AUTHOR]

We directly compare the effect of metallic titanium (Ti) and insulating titanium dioxide (TiO2) on the transport properties of single layer graphene. The deposition of Ti results in substantial n-type doping and a reduction in graphene mobility by charged impurity scattering. Subsequent exposure to oxygen largely reduces the doping and scattering by converting Ti into TiO2. In addition, we observe evidence for short-range scattering by TiO2 impurities. These results illustrate the contrasting scattering mechanisms for identical spatial distributions of metallic and insulating adsorbates. [ABSTRACT FROM AUTHOR]

Controlling the interaction of a single quantum emitter with its environment is a key challenge in quantum optics. Here, we demonstrate deterministic coupling of single nitrogen-vacancy (NV) centers to high-quality photonic crystal cavities. We preselect single NV centers and position their 50-nm-sized host nanocrystals into the mode maximum of photonic crystal S1 cavities with few-nanometer accuracy. The coupling results in a strong enhancement of NV center emission at the cavity wavelength. [ABSTRACT FROM AUTHOR]

Room-temperature ferromagnetism has been observed in high density free-standing CrSi2(core)/SiO2(shell) semiconducting nanocables, which is contrast to diamagnetic properties of both CrSi2 and SiO2 in bulk. The hexagonal CrSi2 C40-type nanowires, sheathed with a thin amorphous SiO2 layer, grow along [0001] direction. The results of first-principles simulations indicate that Cr atoms around the interface are with anomalously high magnetization (about 2 μB/atom), due to distorted/dangling bonds and surrounded oxygen atoms. Evaluations can be very consistent with measurements by further considering the effects of interfacial roughness and more distribution of oxygen around the interface. These results point toward a different way to tune nanomagnetism in core/shell nanowires. [ABSTRACT FROM AUTHOR]

Charge carrier lifetime is a critical parameter to improve the conversion efficiency of radioisotope power sources and the sensitivity of neutron detectors based on boron carbide thin films. The effective charge carrier lifetime in B4C boron carbide films has been investigated by using transient photoconductivity decay. The carrier lifetime depends on the characterization conditions as well as the structure of the films. The measured lifetime could be up to ∼1 ms in B4C film, which is much longer than that in conventional semiconductors. The photoresistance change in B4C films and the photovoltaic response of B4C/n-Si(100) heterojunctions have also been studied. [ABSTRACT FROM AUTHOR]

Two cubic, single crystal silicon carbide (3C-SiC) films with similar thickness are shown to exhibit significantly different optical properties at mid-infrared wavelengths. Depth profiling by time-of-flight secondary ion mass spectroscopy indicates that these two films have substantially different n-type impurity concentrations that are responsible for the observed differences in optical absorption. The influence of impurities manifests as substantially different planar defect morphologies. [ABSTRACT FROM AUTHOR]

In this letter, we present direct and unambiguous experimental evidence for nonthermal illumination effects in boron or arsenic implanted silicon. Both, dopant diffusion and activation vary significantly with illumination. Depending on annealing temperature, diffusion is either enhanced or inhibited. The results have significant implications for modeling and formation of ultrashallow junctions. [ABSTRACT FROM AUTHOR]

The Raman shift of Δω3 in (001) strained silicon is found to be independent of the azimuthal angle of the patterned structures but exhibits shape dependence in strain relaxation. The tensile strain is reduced from 0.85% in the unpatterned thin film to 0.16% in the cylindrical pillars showing 82% relaxation. It becomes more significant along the width direction of the patterned gratings due to Poisson's effect and only a tensile strain of 0.07% remains. Consequently, the strain state changes from biaxial into uniaxial and is expected to enhance the carrier mobility. Finite element analysis is conducted to elucidate the mechanism. [ABSTRACT FROM AUTHOR]

We propose an optomechanical structure consisting of a photonic-crystal (holey) membrane suspended above a layered silicon-on-insulator substrate in which resonant bonding/antibonding optical forces created by externally incident light from above enable all-optical control and actuation of stiction effects induced by the Casimir force. In this way, one can control how the Casimir force is expressed in the mechanical dynamics of the membrane, not by changing the Casimir force directly but by optically modifying the geometry and counteracting the mechanical spring constant to bring the system in or out of regimes where Casimir physics dominate. The same optical response (reflection spectrum) of the membrane to the incident light can be exploited to accurately measure the effects of the Casimir force on the equilibrium separation of the membrane. [ABSTRACT FROM AUTHOR]

This work investigates the emission properties of single color centers in natural diamond nanoparticles for potential use as single photon sources and photostable biomarkers. Two emitters, H3 and H4, were identified by their sharp zero-phonon lines at 503 nm and 496 nm, respectively, in the photoluminescence spectra. Using a modified Hanbury Brown and Twiss setup, we observed complete photon antibunching for the H3 center. No fluorescence blinking was detected for a single H3 emitter on the ms timescale, indicating weak coupling between the electronic transition 1A1↔1B1 and adjacent metastable states of this nitrogen-vacancy-nitrogen point defect. [ABSTRACT FROM AUTHOR]

We report first-principles calculations and interface simulations for Zn3P2, a compound that may form during doping of ZnO with phosphorous. While P is a deep acceptor in ZnO and thus unable to produce p-type conductivity, we show that hole accumulation can occur at ZnO/Zn3P2 interfaces due to the unusual valence-band alignment between the two materials. This provides an explanation for the hole conductivity that has been observed in Hall measurements on phosphorous-doped ZnO. [ABSTRACT FROM AUTHOR]

We investigate the carrier transport characteristics in strained n-channel metal-oxide-semiconductor field effect transistors (nFETs) with embedded silicon-carbon (Si:C) source/drain (S/D) stressors formed in close proximity to the channel, taking parasitic resistance into account in the extraction of carrier transport parameters. While bringing the Si:C S/D stressors closer to the channel improves their effectiveness in imparting tensile strain to the channel, degradation in ballistic efficiency due to increased carrier scattering is observed. Fortunately, this is more than compensated by an increase in the carrier injection velocity vinj. For channel-proximate (CP) Si:C S/D nFETs with gate lengths ranging from 100 to 130 nm, a ∼10% drive current IDsat enhancement is observed with a ∼15% improvement in vinj. These findings clarified experimentally that in addition to mobility enhancement, vinj improvement also plays a significant role in the IDsat enhancement achieved by CP Si:C S/D nFETs. [ABSTRACT FROM AUTHOR]

The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) materials, that occurs during thermal annealing experiments, has been analyzed by Raman spectroscopy and differential scanning calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by relaxation of the Si–Si network strain but it reveals a derelaxation of the bond angle strain. Since the state of relaxation after annealing is very similar for pure and hydrogenated materials, our results give strong experimental support to the predicted configurational gap between a-Si and crystalline silicon. [ABSTRACT FROM AUTHOR]

We have quantitatively studied by transmission electron microscopy the growth kinetics of platelets formed during the continuous hydrogenation of a Si substrate/SiGe/Si heterostructure. We have evidenced and explained the massive transfer of hydrogen from a population of platelets initially generated in the upper Si layer by plasma hydrogenation towards a population of larger platelets located in the SiGe layer. We demonstrate that this type of process can be used not only to precisely localize the micro-cracks, then the fracture line at a given depth but also to “clean” the top layer from pre-existing defects. [ABSTRACT FROM AUTHOR]